US3763947A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tractor four wheel drive
Assignee: Deutz Allis Corp
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Filing: 1971-09-21
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Granted: 1973-10-09
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Expires: 1991-09-21
Abstract
Abstract A four wheel drive for a vehicle having means for synchronizing the ground speeds of the front wheels and the rear wheels through selectively different drive ratios between the front and rear wheels as the front wheel rolling radius is changed.
Inventors
- 👤 D Longshore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:15
CPC Classifications
B; B60; B60K; B60K17/00; B60K17/34; B60K17/348; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19219
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
263 words
A four wheel drive for a vehicle comprising, a power transmission adapted for connection to an engine including a drive gear, a pair of rear wheels defining a predetermined rolling radius, a rear drive assembly for transmitting power from said transmission to said rear wheels, a pair of front wheels defining a predetermined rolling radius, a front wheel drive mechanism for driving said front wheels, a power transfer mechanism connected between said front wheel drive mechanism and said transmission including, a driven gear meshing with said drive gear, means selectively changing the operating pitch circle of said driven gear relative to said drive gear including, a transfer gear case, means supporting said driven gear in said transfer gear case selectively at any one of a number of gear centers, said driven gear selectively including any one of a number of gears each including a different number of gear teeth, and each driven gear defining teeth of any one selected tooth thickness of a plurality of tooth thicknesses to thereby selectively change the operating pitch circle of said driven gear by selective and alternative changing of the gear center position of said driven gear or changing the operating pitch circles of said drive gear and said driven gear by changing of the tooth thickness of said driven gear to provide one of a selected number of gear ratios from said transmission through said front wheel drive mechanism to provide a predetermined ground speed of the front wheels relative to the rear wheels to compensate for any change in rolling radius of the front wheels.
Claim 2
Dependent Claim
263 words
A four wheel drive for a vehicle comprising, a power transmission adapted for connection to an engine including a drive gear, a pair of rear wheels defining a predetermined rolling radius, a rear drive assembly for transmitting power from said transmission to said rear wheels, a pair of front wheels defining a predetermined rolling radius, a front wheel drive mechanism for driving said front wheels, a power transfer mechanism connected between said front wheel drive mechanism and said transmission including, a driven gear meshing with said drive gear, means selectively changing the operating pitch circle of said driven gear relative to said drive gear including, a transfer gear case, means supporting said driven gear in said transfer gear case selectively at any one of a number of gear centers, said driven gear selectively including any one of a number of gears each including a different number of gear teeth, and each driven gear defining teeth of any one selected tooth thickness of a plurality of tooth thicknesses to thereby selectively change the operating pitch circle of said driven gear by selective and alternative changing of the gear center position of said driven gear or changing the operating pitch circles of said drive gear and said driven gear by changing of the tooth thickness of said driven gear to provide one of a selected number of gear ratios from said transmission through said front wheel drive mechanism to provide a predetermined ground speed of the front wheels relative to the rear wheels to compensate for any change in rolling radius of the front wheels.
Claim 3
Dependent Claim
61 words
A four wheel drive for a vehicle as set forth in claim 1 including a transmission housing supporting said drive gear, said transfer gear case mounted on said housing rotatably supporting said driven gear at a first gear center with said driven gear defining a predetermined number of gear teeth thereby providinG a first speed ratio for driving the front wheels.
Claim 4
Dependent Claim
67 words
A four wheel drive for a vehicle as set forth in claim 1 including a transmission housing supporting said drive gear, a shim mounted between said transfer gear case and said transmission housing to position said driven gear at a second gear center, said driven gear defining said predetermined number of gear teeth plus one to thereby provide a second speed ratio for driving said front wheels.
Claim 5
Dependent Claim
88 words
A four wheel drive for a vehicle as set forth in claim 1 including a transmission housing supporting said drive gear, a shim positioned between said transmission housing and said transfer gear case for positioning said driven gear at a second gear center, said driven gear including said predetermined number of gear teeth plus two, said driven gear defining gear teeth of less thickness than said drive gear to accommodate operation on said second gear center and for providing a third speed ratio for driving the front wheels.
Claim 6
Dependent Claim
38 words
A four wheel drive for a vehicle as set forth in claim 1 wherein said drive gear and said driven gear define a circular pitch substantially equal to twice the circular tooth thickness on the operating pitch circle.
Claim 7
Dependent Claim
41 words
A four wheel drive for a vehicle as set forth in claim 1 wherein the driven gear defines a circular pitch substantially greater than twice the circular thickness of a gear tooth on the operating pitch circle of said driven gear.
Claim 8
Dependent Claim
67 words
A four wheel drive for a vehicle as set forth in claim 1 wherein the circular pitch is substantially greater than twice the circular tooth thickness thereby shifting the operating pitch circle away from the gear center of said driven tooth and shifting the operating pitch circle toward the gear center of said drive gear to decrease the speed ratio from the drive to the driven gear.
Claim 9
Dependent Claim
54 words
A four wheel drive for a vehicle as set forth in claim 1 wherein said drive defines a circular pitch equal to substnatially twice the circular tooth thickness, said driven gear defining a circular pitch substantially greater than twice the circular tooth thickness to thereby provide a short addendum tooth for said driven gear.
Claim 10
Dependent Claim
54 words
A four wheel drive for a vehicle as set forth in claim 1 wherein said driven gear defines a circular pitch substantially greater than twice the circular tooth thickness, said driven gear defines a short addendum tooth profile to effectively increase the operating pitch circle of said driven gear relative to said drive gear.
Claim 11
Dependent Claim
83 words
A four wheel drive for a vehicle as set forth in claim 1 wherein said means supporting said driven gear includes a transmission housing, said transfer gear case, a shim positioned between said transmission housing and said transfer gear case to define a gear center for said driven gear, said driven gear defines a circular pitch substantially greater than twice the circular tooth thickness to thereby define a short addendum tooth profile for effectively increasing the operating pitch circle of said driven gear.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |